Proportion of Glacially To Fluvially Induced Quartz Grain Microtextures Along the Chitina River, SE Alaska, U.S.A.

Sweet, Dustin E.; Brannan, David Keith

doi:10.2110/jsr.2016.49

Cited by 23 publications

(41 citation statements)

References 46 publications

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“…8). In addition, grains with v-shaped percussion marks indicative of transport by meltwater streams were also noted 45,75 . Images were analyzed for the presence (1) or absence (0) of each microtexture on the list and frequency percent was calculated for each sample.…”

Section: Diatoms a Total Of 66 Samples Were Processed For Diatom Anamentioning

confidence: 99%

Sediment controls dynamic behavior of a Cordilleran Ice Stream at the Last Glacial Maximum

et al. 2020

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The uncertain response of marine terminating outlet glaciers to climate change at time scales beyond short-term observation limits models of future sea level rise. At temperate tidewater margins, abundant subglacial meltwater forms morainal banks (marine shoals) or ice-contact deltas that reduce water depth, stabilizing grounding lines and slowing or reversing glacial retreat. Here we present a radiocarbon-dated record from Integrated Ocean Drilling Program (IODP) Site U1421 that tracks the terminus of the largest Alaskan Cordilleran Ice Sheet outlet glacier during Last Glacial Maximum climate transitions. Sedimentation rates, ice-rafted debris, and microfossil and biogeochemical proxies, show repeated abrupt collapses and slow advances typical of the tidewater glacier cycle observed in modern systems. When global sea level rise exceeded the local rate of bank building, the cycle of readvances stopped leading to irreversible retreat. These results support theory that suggests sediment dynamics can control tidewater terminus position on an open shelf under temperate conditions delaying climate-driven retreat.

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Section: Diatoms a Total Of 66 Samples Were Processed For Diatom Anamentioning

confidence: 99%

Sediment controls dynamic behavior of a Cordilleran Ice Stream at the Last Glacial Maximum

et al. 2020

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“…-Since the modern glacial environment is strongly linked with highly dynamic meltwater regimes including episodes of extremely intense runoff (Carrivick et al 2016 ), a number of aqueous-induced textures on the quartz grains should be considered. These are rounded outlines, low reliefs and impact v-shaped marks (Mahaney 1998;Mahaney and Kalm 2000;Madhavaraju et al 2006), which are produced during grain-on-grain impact in low-viscosity media (Sweet and Brannan 2016 ).…”

Section: Discussionmentioning

confidence: 99%

“…Partially following the methods of Vos et al (2014), the types of microtextures, as of mechanical, chemical and combined origin, together with a general grain outline have been semi-quantified based upon their occurrence (= frequency distribution, in which the statistics are based on the number of grains exhibiting a specific microtexture within a sample) as abundant (>75%), common (50-74%), medium (26-49%), sparse (6-25%), rare (<5%) and not observed. Finally, we grouped microtextures of mechanical origin as high-stress, percussion and polygenic features (Sweet and Soreghan 2010), and further calculated the ratio of fluvially to glacially induced microtextures (F/G) according to proposal of Sweet and Brannan (2016).…”

Section: Methodsmentioning

confidence: 99%

Quartz grain features in modern glacial and proglacial environments: A microscopic study from the Russell Glacier, southwest Greenland

Kalińska¹,

Lamsters²,

Karušs³

et al. 2017

Polish Polar Research

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This paper provides an overview of the results of research on changes in ground temperature down to 50 cm depth, on the Kaffiøyra Plain, Spitsbergen in the summer seasons. To achieve this, measurement data were analysed from three different ecotopes (CALM Site P2A, P2B and P2C) -a beach, a moraine and tundra -collected during 22 polar expeditions between 1975 and 2014. To ensure comparability, data sets for the common period from 21 July to 31 August (referred to as the "summer season" further in the text) were analysed. The greatest influence on temperature across the inves− tigated ground layers comes from air temperature (correlation coefficients ranging from 0.61 to 0.84). For the purpose of the analysis of the changes in ground temperature in the years 1975-2014, missing data for certain summer seasons were reconstructed on the ba− sis of similar data from a meteorological station at Ny−Ålesund. The ground temperature at the Beach site demonstrated a statistically−significant growing trend: at depths from 1 to 10 cm the temperature increased by 0.27-0.28°C per decade, and from 20 to 50 cm by as much as 0.30°C per decade. On the Kaffiøyra Plain, the North Atlantic Oscillation (NAO) has a greater influence on the ground and air temperature than the Arctic Oscilla− tion (AO).

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“…Of the four glacial sediment samples collected at this location, two samples (JIF19-C26-01 and JIF19-C26-04) were collected from a glaciofluvial melt stream 10 m downstream from the dead ice, and the remaining samples (JIF19-C26-02 and JIF19-C26-03) were collected from recently-inactive lateral moraines. Because many kilometers of fluvial transport are needed to create a fluvial microtextural overprint on glacial sediment (Pippin 2016;Sweet and Brannan 2016;Křížek et al 2017), samples JIF19-C26-01 and JIF19-C26-04 are more representative of a glacial setting than a fluvial setting.…”

mentioning

confidence: 99%

“…1; Table 1). We selected 5 studies to use in this modern dataset: Mahaney et al (1996), Stevic (2015), Sweet and Brannan (2016), Kalińska-Nartiša et al (2017), andSmith et al (2018). Mahaney et al (1996) analyzed 11 glacial samples distributed around the Antarctic continent.…”

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confidence: 99%

Meta-analysis of Cryogenian through modern quartz microtextures reveals sediment transport histories

Reahl

Cantine

Wilcots

et al. 2020

Preprint

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Quantitative scanning electron microscopy (SEM) quartz microtextural analysis can reveal the transport histories of modern and ancient sediments. However, because workers identify and count microtextures differently, it is difficult to directly compare quantitative microtextural data analyzed by multiple workers. As a result, the defining microtextures of certain transport modes and their probabilities of occurrence are not well constrained. We used principal component analysis (PCA) to directly compare modern and ancient aeolian, fluvial, and glacial samples from the literature with 9 new samples from active aeolian and glacial environments. Our results demonstrate that PCA can group microtextural samples by transport mode and identify the microtextures that differentiate between aeolian and fluvial/glacial transport modes, regardless of study. The PCA ordinations indicate that aeolian samples are distinct from fluvial and glacial samples, which are in turn difficult to disambiguate from each other. The ancient and modern sediments are also shown to have quantitatively similar microtextural relationships. Therefore, PCA may be a useful tool to constrain the ambiguous transport histories of some ancient sediment grains. As a case study, we analyzed two samples with ambiguous transport histories from the Cryogenian Bråvika Member (Svalbard). Integrating PCA with field observations, we find evidence that the Bråvika Member facies investigated here includes aeolian deposition and may be analogous to syn-glacial Marinoan aeolian units including the Bakoye Formation in Mali and the Whyalla Sandstone in South Australia.

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Proportion of Glacially To Fluvially Induced Quartz Grain Microtextures Along the Chitina River, SE Alaska, U.S.A.

Cited by 23 publications

References 46 publications

Sediment controls dynamic behavior of a Cordilleran Ice Stream at the Last Glacial Maximum

Sediment controls dynamic behavior of a Cordilleran Ice Stream at the Last Glacial Maximum

Quartz grain features in modern glacial and proglacial environments: A microscopic study from the Russell Glacier, southwest Greenland

Meta-analysis of Cryogenian through modern quartz microtextures reveals sediment transport histories

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